In order to make an artificial tooth, crown, or other dental prosthetic, dentists usually require a dental model. Conventionally, such a model is formed by the impression left in a dental impression tray filled with a self-hardening, gum-like compound. To form the impression, the tray is inserted into the patient's mouth and the compound fills in the area around the teeth before hardening. After removing the tray and compound from the mouth, a model material is poured into the dental impression and hardens to form the model of the patient's teeth.
When preparing a crown for a tooth, the tooth is typically prepared by reshaping and reducing its size. This enables the crown to fit over the tooth without disrupting the patient's other teeth. Once the tooth is reshaped, a thin piece of retraction cord is typically placed around it before a dental impression is taken. This impression is used to form the model that the dentist will use when constructing the crown.
As can be imagined, the crown must be formed to fit precisely on the reshaped tooth and between the adjacent teeth. Furthermore, the crown must not obstruct the patient's bite. Therefore, it is vital that the dental impression be accurate so that the proper crown can be prepared. Unfortunately, dental impressions prepared under the currently practiced method often suffer from significant inaccuracies. Some inaccuracies are caused by the movement of the patient's tongue, lips, cheeks or jaw. Other inaccuracies are due to the fact that the impression material tends not to adhere tightly to the teeth since it is designed to be easily removed from the teeth. As a result, the models prepared from these faulty dental impressions share their inaccuracies. More importantly, the crowns or other dental prosthetics formed using the models also include their inaccuracies. In order to overcome this, dentists often must alter the crown when mounting it to the reshaped tooth—a process that can be difficult for both the dentist and the patient.
In light of the above, it is an object of the present invention to provide devices and methods for forming a mold for a dental model having improved accuracy. Another object of the present invention is to provide devices and methods for forming a mold for a dental model that uses suction to draw the moldable material into contact with the teeth. It is yet another object of the present invention to provide devices and methods for forming a dental impression in which an impression of the patient's tooth is taken before a final mold of the reshaped tooth is taken within the impression. Another object of the present invention is to provide dental impression devices and methods that allow for selective suctioning of moldable material within the patient's mouth. Still another object of the present invention is to provide devices for forming dental impressions, and methods of using the devices, that are relatively easy to manufacture, simple to use and comparatively cost effective.